This application claims the benefit of Korean Application No. 2000-79735 filed Dec. 21, 2000, in the Korean Patent Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a disk player, a turntable, a clamper and a spindle motor which are employed in the disk player, and more particularly, to a disk player provided with a self-compensating dynamic balancer so that internal vibrations due to eccentric mass of a disk can be limited, a self-compensating-dynamic-balancer integrated turntable, a self-compensating-dynamic-balancer integrated clamper, and a self-compensating-dynamic-balancer integrated spindle motor which are employed in the disk player.
2. Description of the Related Art
In general, a disk player is an apparatus for recording information on a recording medium such as a compact disk (CD), a CD-ROM, or a digital versatile disk (DVD), or reproducing information recorded from the recording medium. The disk and an optical pickup are required to be protected against external impact and internal vibrations.
A conventional disk player is shown in FIG. 1. A deck base 10 is hinged to a housing (not shown) to pivot in a vertical direction and a deck plate 20 is attached to the deck base 10. A spindle motor 21, installed at the deck plate 20 to provide a rotational force for a disk 1, has a turntable 23 fixed to a shaft 22 of the spindle motor 21. A disk 1 is placed on the turntable 23. A clamper 40 is installed at the upper inner surface of the housing to face the turntable 23 for clamping the disk 1 on the turntable 23, and an optical pickup 25 is installed at the deck plate 20 to be movable in a radial direction of the disk 1 for performing recording and reproducing operations. The disk player is provided with damper members 30 installed between the deck base 10 and the deck plate 20 so that external vibrations transferred via the deck base 10 are not transferred directly to the deck plate 20, the spindle motor 21 and the optical pickup 25. The damper members 30 are made of a material not having a high strength, such as a soft rubber or polyurethane, so as to absorb external impacts well.
The disk player of FIG. 1 protects the disk 1 and the optical pickup 25 from external impact by employing the damper members 30. However, the disk player of FIG. 1 includes no measures for reducing internal vibrations occurring due to an eccentric mass of the disk 1 where the spindle motor 21 rotates. Here, the eccentric mass of the disk is produced by variations in a manufacturing process of the disk 1. The eccentric mass causes whirling, that is, the revolution of the rotation axis of the spindle motor due to a disparity between the center of rotation of the disk 1 and the center of mass of the disk.
The influence of whirling on the spindle motor 21 is not significant in a low-speed model, such as a base- or a dual-speed model, but the whirling influence is so serious in a high speed model, such as a six-speed or eight-speed model, that recording/reproduction of information can be difficult. To compensate for the whirling influence in a conventional high speed disk player, a deck plate at which a spindle motor is installed is made to have a greater mass, or the damper members are made stronger so that undesirable movement of a deck plate due to an eccentric mass of a disk is reduced.
The effect on whirling of increasing the mass of the deck plate is insignificant where the disk player operates at a high speed. Additionally, an increase in mass increases manufacturing cost, and limits compactness of the disk player. Where the damper members strength is increased, the damper members do not effectively block vibrations and impact transferred from outside the disk player.
To solve the above problems, it is a first object of the present invention to provide a disk player which limits internal vibrations due to eccentric mass of a disk without increasing the mass of the disk player and which reduces an influence of external vibrations.
It is a second object of the present invention to provide a self-compensating-dynamic-balancer integrated turntable employable in a disk player to limit internal vibrations due to eccentric mass of a disk.
It is a third object of the present invention to provide a self-compensating-dynamic-balancer integrated clamper empoyable in a disk player to limit internal vibrations due to eccentric mass of a disk.
It is a fourth object of the present invention to provide a self-compensating-dynamic-balancer integrated spindle motor employable in a disk player to limit internal vibrations due to eccentric mass of a disk.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and, in part, will be obvious from the description, or may be learned by practice of the invention.
Accordingly, to achieve the first and other objects, there is provided a disk player comprising: a deck base; a deck plate elastically attached to the deck base; damper members interposed between the deck base and the deck plate so that the deck plate can be protected from external impact; a spindle motor installed at the deck plate for providing rotational force to a disk; a turntable which is installed on the rotation shaft of the spindle motor, and on which the disk is placed; a damper for clamping the disk placed on the turntable; an optical pickup installed on the deck plate for recording and/or reproducing information on/from the disk; and a self-compensating dynamic balancer which is installed in a cavity provided in at least one rotating member and the center of mass thereof is disposed at a position opposite the center of mass of the disk with respect to the rotation shaft of the spindle motor due to respective centrifugal forces where the disk rotates, wherein external vibrations are prevented from being transferred to the deck plate by the damper members, and internal vibrations generated by an eccentric center of mass of the disk are limited by the self-compensating dynamic balancer.
To achieve the second and other objects, there is provided a self-compensating-dynamic-balancer integrated turntable for a disk player comprising: a cylindrical turntable main body fixed to the rotation shaft of a spindle motor and provided with a cavity therein; movable members movably disposed in the cavity; and a cover member joined to an opening of the main body so as to cover the main body, and provided with an engagement projection on the upper surface thereof to which the center hole of the disk is fitted so that the disk can be seated thereon.
To achieve the third and other objects, there is provided a self-compensating-dynamic-balancer integrated damper for a disk player comprising: a cylindrical clamper main body installed on a deck base to be rotated by a rotational force of a spindle motor, and provided with a cavity; a pressing member installed at the clamper main body for pressing a disk placed on a turntable; movable members movably disposed in the cavity of the clamper main body; and a cover member joined to an opening of the main body for covering the cavity.
To achieve the fourth and other objects, there is provided a self-compensating-dynamic-balancer integrated spindle motor for a disk player comprising: a motor base to be screwed to a deck plate; a stator fixed to the motor base; a rotor installed to be rotatable with respect to the stator; a cylindrical case attached to the rotor to form a cavity therebetween, and movable members movably disposed in the case.